Sources and Uncertainty
The accounts of Synetus are brief and not fully consistent on chronology. The Orthodox Church in America's synaxarion notes his service as a reader under Pope Sixtus (257-258) but does not name the emperor under whom he suffered. OrthodoxWiki dates his martyrdom to 270-275, the reign of Aurelian. These notices preserve only his office, his manner of death, and the approximate period of his witness.